THE HYDROGEOLOGIC CYCLE OF MARS, PAST AND PRESENT: IMPLICATIONS OF LIFE

All three physical states of water have been present on Mars for a large amount of the planet's geologic history, according to my research. Given what we presuppose as the life-yielding properties of water, we can assume that there were incidences of life as we know it on Mars, too. I have compiled studies from professional research and scholarly interpretation of data that indicate spatial orientations of liquid water presence and movement across the surface of Mars. The presence of phyllosilicates, hematite concentrations called “blueberries”, hydrated sulfates, evaporites, festooned trough cross-bedding, gullies and valley networks reminiscent of water flow, and terraced fan deposits are chemical and sedimentological testimony to the incidence of moving and standing H2O(liquid). The Mars Rovers Spirit and Opportunity have contributed extensive raw data for our scrutiny; as have Mars Reconnaissance Orbiter, the European Space Agency's Mars Express, Mars Global Surveyor, Mars Odyssey, and the Viking and Mariner missions. Ground-based observations have also been very useful. Mars has temperatures and pressures that lie throughout the H2O phase diagram; therefore, it has a water cycle that involves all three natural phases of water. This is possible because the obliquity of Mars' ecliptic allows for seasonal variations. With this assumption, it is easy to see a likelihood of life existing on Mars; however, this life is not yet evident due to harsh conditions on the surface. What lies beneath the surface at the shallowest kilometer is what we are concerned with when inquiring about life at Mars. I propose that there are places in the subsurface where conditions that are right have been continual for long enough time for life to evolve and be sustained. These conditions may include environments that are suited to host communities of organisms with a wide array of complexity and type.